The present invention relates to luggage, in particuar lar to a suitcase or briefcase, which is fitted with a central part consisting of two mutually linked, mechanically strong half-frames acting as supports for two shelves or trays spanning the inside space of said luggage.
Such luggage is generally known and widely marketed in the form of carrying cases, briefcases or wheeled suitcases. In general each half-frame of the central part comprises a grip side, a hinging side opposite said grip side, and two mutually opposite lateral parts. The frame and/or the trays may assume arbitrary shapes, for instance rectangular, round or oval.
As regards manufacture, the costliest part of a suitcase case or briefcase is the central part with the two mutually linked half-frames which typically are fitted with, in addition to the hinge, suitcase locks and grips. Presently the frame is generally made of plastic. If use is made of correspondingly high-grade, mechanically strong plastic and of locks of long service lives, then the manufacturing costs of the central part shall be the major portion of the overall suitcase manufacturing costs. As regards plastic-tray suitcases, the trays as a rule are manufactured integrally with the corresponding half-frames, whereas, with cloth or leather suitcases, the corresponding trays are affixed in a very expensive manner onto a metal or plastic frame.
Desirably the manufacturing costs of such suitcases should be reduced by manufacturing in large numbers the other-wise complex and costly frame. However the manufacture of large numbers of components is best attainable if the same component is used in many different models. In the present instance, different suitcases with the same kind of frames should there-fore be manufactured. Moreover the same frame ought to be use-able for suitcases using hard trays and suitcases fitted with soft trays.
As regards conventional suitcases, for instance small or travel suitcases, the volume of the suitcase""s inside space most of the time will be constant. As a result different packing volumes will require different suitcases. For a business trip of only a few days, for instance, a smaller suitcase will be needed than on a vacation of several weeks. On the other hand the cost of acquiring several suitcases of different sizes is high, and the suitcases take up much storage space.
In view of this problem, application""s U.S. Pat. No. 6,050,373 proposes a suitcases offering variable capacity wherein the suitcases trays are detachably affixed to the half-frames of a central part. Consequently the user may resort to trays of different depths and/or to trays of different shapes while keeping the same central part. In this manner the suitcase capacity can be matched to the particular required packing volume. Applicant""s U.S. Pat. No. 6,234,287 describes an especially simple and user-friendly locking system for such exchangeable suitcase trays. This suitcase""s central part with the two mutually linked half-frames conventionally consists of a light metal or a rigid plastic, whereas the trays either may be made of a rigid plastic to constitute rigid trays or they may be soft trays made of a soft or resilient material such as leather, fabric, cloth or a light sheetmetal. When using soft trays, that tray zone which shell receive the locking means to affix the tray to the particular half-frame must be reinforced to attain local rigidity. Hence soft trays must be fitted in a complex manner at the tray edge with appropriate rigidifying means. If manufacturing costs are to be reduced, it is desirable to connect soft suitcase trays in an easy and economical manner to the half-frames of a central part.
Therefore, it is an object of the present invention to create luggage, in particular a suitcase or a briefcase of the above-described kind, which, while using a high-grade central part, may be manufactured economically and within a wide range of variations. In particular an objective of the present invention is to provide luggage with exchangeable trays as defined in the patent documents U.S. Pat. Nos. 6,050,373 and 6,34,287 wherein soft trays may be used in simple and problem-free manner while the central part is rigid.
Accordingly an object of the present invention is luggage, in particular a suitcase or a briefcase, comprising a central part comprising two mutually linked dimensionally stable half-frames acting as supports for trays defining the inner space of the luggage, wherein said luggage includes a connecting frame mounted between each half-frame and an associated tray, the connecting frame being fitted with a channel into which the tray is affixed. The connecting frame in accordance with the present invention permits manufacturing a suitcase or a brief-case with very diverse trays. The manufacturing procedure only requires that the particular tray being used be inserted into the connecting frame""s channel and then be affixed therein. Accordingly, production may be carried out very economically. The trays may be made of selected materials and may have different shapes and colors. Only the rim of the tray needs to be designed in such a manner as to correspond to said channel""s contour and width. Consequently the same frame may be used both for plastic hard trays and, for instance, leather, cloth or aluminum soft trays.
Preferably the connecting channel is peripheral, so that, following insertion of a tray into it, a half-suitcase is subtended which is tightly closed relative to the ambient. Furthermore, appropriate seals such as sealing tape or sealing lips may be mounted inside said channel.
In one variation of the luggage of the invention, the trays are inserted in a frictionally and/or geometrically locking manner into the channel and in general thereafter are longer removable by the user. For instance, the trays may be press-fitted during manufacture into the channel of which the inside width is slightly less than the tray""s rim thickness. Moreover detent elements may be fitted into the channel and said channel may be engaged by complementary locking elements at the tray""s rim when the tray is inserted into the channel.
To reliably affix the tray into the channel; connecting means other than said frictional and/or geometric connection of tray and connecting frame may be used instead of or besides these latter to affix the tray into the connecting frame""s channel. Illustratively the tray may be glued into the channel or be fused with, riveted or sewed into the connecting frame. In a preferred embodiment, the tray is sewn into the connecting frame which in this case preferably is fitted with a channel having a projecting wall that supports the tray when the latter is inserted. Thereupon, using appropriate industrial sewing machines, the seam may be placed in the zone of the projecting wall. Such sewing machines stitching layers of cloth and plastic typically 10 to 20 mm thick are known.
In a first embodiment of the luggage of the present invention, the connecting frame and the associated half-frame are integral. In such case the connecting frame and the half-frame preferably will be an integral, plastic injection-molded component. This particular embodiment of the invention essentially is intended to lower the manufacturing costs of luggage, the same central part being manufacturable jointly with the most diverse trays and therefore the most expensive suitcase component may be produced in large numbers while at the same time, the invention contemplates varying the trays used in the manufacturing procedure, so that a large number of different suitcases can be made.
With respect to a suitcase offering trays exchangeable by the user in the manner of a suitcase disclosed in U.S. Pat. Nos. 6,050,373 and 6,234,287, the connecting frame defined in a second embodiment of the present invention is designed to be connected so as to be detachable from the associated half-frame by the user. In this embodiment the desired trays are inserted and firmly affixed into the channel of the connecting frame during manufacture. If the user wants to use the same central part but with different trays, such user will exchange the subassembly of a particular tray and an attached connecting frame. Considering that locking elements fasten the sub-assembly of a connecting frame and tray to the half frame, which in general shall be rigid, the manufacturing costs for this embodiment also shall be significantly lowered because in this instance as well the detachable connecting frame can be produced in large runs, and still the manufacturer may equip the connecting frame with very different trays, be they hard frames or, preferably, soft trays, of the most diverse shapes, colors and designs. Different trays also may be manufactured very economically because the trays of the luggage of the invention consist merely of the tray proper, that is, they are devoid of any hinge or locking elements.
Preferably the connecting frame shall be an injection-molded component, for instance made of plastic. Illustratively an injection mold may be used to make the connecting frame, said mold being fitted with adjustable slides, whereby the channel width of the connecting frame can be changed by correspondingly adjusting the slides and thus matching such frame to the desired tray thickness.
In case the suitcase comprises a detachable subassembly of tray and connecting-frame, this connecting frame preferably will be dimensioned to terminate flush with the particular half-frame in such manner that only the tray will be visible from the outside.
The luggage of the invention fitted with the connecting frame constituting the transition component between tray and half-frame is especially appropriate for soft-tray suitcases where the tray for instance is made of leather, cloth, soft plastic or aluminum sheetmetal or another light sheet metal.
An illustrative embodiment of the luggage of the invention is elucidated below in relation to the attached drawings.